A display or light-modulating device incorporates one or more measures of liquid that obstruct or filter light that passes onto or through the liquid; a space distribution of different light-modulating filters, optical instrument or materials or of materials that change the frequency or color of light passing onto or through them, to emit a different frequency or color of light; and means to apply electrowetting effect to controllably modulate the location or shape of one or more measures of a polar or conductive liquid, so that at least some portion of one or more light-obstructing or light-filtering measures of liquids is caused to be located between one or more light sources and the space distribution of light-modulating filters, optical instruments or light-modulating materials, or said space distribution of materials that change the frequency or color of light passing onto or through them, to emit a different frequency or color of light, thereby controllably modulating properties of light emitted from said device.